No abstract

Diagnosis and Recommendation Integrated System (DRIS) is widely used statistical approach for interpretation of the plant tissue analysis data and to diagnose the plant nutreint needs much earlier than the reduction of crop yield with greater accuracy. It helps in simultaneous identifying imbalances, deficiencies and excesses of crop nutrients and ranks them in the order of their importance for their remedial steps. The DRIS norms based on foliar composition can developed in any crop and at any stage of its development. It provides a mathematical means of ordering large number of nutrient ratios into nutrient indices that can be easily interpreted. The nutrient ranges been established as deficient, low, optimum, high and excessive based on the mean of nutrient concentration and standard deviation from high yielding population to serve as a guide for a quick and routine diagnostic and advisory purpose. The major advantage of DRIS lies in its ability to minimize the effect of variation in tissue age on diagnosis, which allows a choice of wider range of tissues than permissible under the conventional critical value approach. Thus, DRIS is holistic in nature for identification of nutrient imbalance in crops and formulation of nutrient management strategies for achieving higher yields.

About 85% farmers of the north eastern hill region (NEHR) of India are small and marginal. Hence, there is need for establishing package of practices in an integrated manner to enhance on-farm resource recycling, employment, income and sustain soil health. An integrated organic farming system (IOFS) model (0. 43 ha) was assessed during 2005- 2017 at ICAR Research Complex for NEH Region, Umiam, Meghalaya (960 m ASL) with diversified farming components like field crops, horticultural crops, livestock (one cow + calf) along with perennial fodder crops, central water harvesting pond for composite fish culture and as a source for irrigation during lean season and provision for nutrient recycling. The productivity and income from the on farm IOFS model was compared with the ruling farmers practice-I (Monocropping, i.e. rice-fallow system) and farmers practice-II (cultivating about 30% farm area for second crop like vegetables after rice). The average results indicated that the rice equivalent yield (REY) from the IOFS model was 19. 8 t/ha as against 4 t/ha and 6.72 t/ha from the farmers practice-I and II, respectively. The enhancement in net income due to IOFS was 355 and 191% relative to farmers practice -I and II, respectively. The IOFS model could meet 92, 82 and 96% (N, P2O5 and K2O) of its nutrient demand within the system. The IOFS model was also replicated in farmers’ field through participatory approach in three villages covering about 110 ha area and 317 households during 2013 to 2017. After 4 years, on an average farmers productivity of various crops (tomato, potato, chili, carrot, French bean, ginger and turmeric) enhanced by 15 to 45% and annual income enhanced by about ` 15500 per house hold. Thus, IOFS could be a viable option for organic food production and sustainable agricultural development in the hill ecosystem of north east India.

Rice (Oryza sativa L.) is the paramount staple crop, providing food to more than 50% people globally. Although, India has attained the apex position in producing rice after China, however, its productivity is still below the world’s average productivity due to several physical abiotic and chemical stress. Silicon (Si) is a multipurpose element that acts as a panacea for multiple stresses. Rice is a heavy accumulator (200–300 kg Si/ha) of Si. Addition of Si prevents movement of heavy metals and salts through cell wall (apoplastic) eventually decreasing their uptake, particularly when rice face iron (Fe) and manganese (Mn) toxicity and increase the rice yield by 20.5–72.7%. Studies have revealed that application of Si mitigates arsenic (As) stress in rice by diminishing its uptake and improving the antioxidants activities. Foliar application of Si increases rice production by 30% under As and cadmium (Cd) contamination conditions. Besides, Si reduces transpiration in rice crop by 30% and also eliminates the effect of heat stress (42.5oC). Further, application of Si in rice has been shown to increase culm strength, integrity and stability of vascular bundle thus, preventing crop against lodging. These review results clearly reveal the importance of Si in imparting abiotic stress tolerance and need for its application in rice crop.